| 摘要 |
PURPOSE:To utilize a bit of a data output without waste by connecting a selector to the data output of a memory used for decoding. CONSTITUTION:A data is selected through select inputs A-C from a ROM 1 and data input 8-bit D0-D7 and the result is outputted to a decode output Y by a selector 2. When the data pattern of 1234 (hexadecimal number) in decode inputs D0-D15, 1234 (hexadecimal number) is inputted to the address input of the ROM 1 and 01 (hexadecimal) is outputted to the data outputs D0-D7. On the other hand, '000' is inputted to the select inputs A-C of the selector 2, a ROM output D0 is selected and outputted to the decode output Y. Since 1 is outputted to the ROM output D0, 1 is outputted to the decode output OUT. Similarly, when 5678 (hexadecimal number) is inputted to the decode inputs D0-D15, 1 is outputted at the decode output OUT. |
